diff --git a/src/modules/ai-job/ai-job.module.ts b/src/modules/ai-job/ai-job.module.ts
index 6bbfe41..b6deea6 100644
--- a/src/modules/ai-job/ai-job.module.ts
+++ b/src/modules/ai-job/ai-job.module.ts
@@ -39,6 +39,8 @@ import { QuizGenerationSnapshotBuilder } from './quiz-generation-snapshot-builde
 import { QuizGenerationExecutor } from './quiz-generation-executor';
 import { QuizGenerationValidator } from './quiz-generation-validator';
 import { QuizGenerationProjector } from './quiz-generation-projector';
+import { LearningAnalysisRegistrationService } from './learning-analysis-registration.service';
+import { LearningAnalysisSnapshotBuilder } from './learning-analysis-snapshot-builder';
 import {
   FeynmanBusinessValidator,
   FeynmanReferenceValidator,
@@ -86,6 +88,8 @@ import { AppConfigModule } from '../config/config.module';
     QuizGenerationExecutor,
     QuizGenerationValidator,
     QuizGenerationProjector,
+    LearningAnalysisRegistrationService,
+    LearningAnalysisSnapshotBuilder,
     { provide: RESULT_PROJECTORS, useFactory: (synthetic: SyntheticResultProjector, activeRecall: ActiveRecallProjector, feynman: FeynmanProjector, reviewCard: ReviewCardGenerationProjector, quiz: QuizGenerationProjector) => [synthetic, activeRecall, feynman, reviewCard, quiz], inject: [SyntheticResultProjector, ActiveRecallProjector, FeynmanProjector, ReviewCardGenerationProjector, QuizGenerationProjector] } as any,
     { provide: AI_JOB_EXECUTION_ENGINE, useExisting: AiJobExecutionEngineImpl },
   ],
diff --git a/src/modules/ai-job/learning-analysis-job-definition.ts b/src/modules/ai-job/learning-analysis-job-definition.ts
new file mode 100644
index 0000000..a0bef9d
--- /dev/null
+++ b/src/modules/ai-job/learning-analysis-job-definition.ts
@@ -0,0 +1,52 @@
+import type { JobDefinition } from './job-definition.types';
+
+export const LEARNING_ANALYSIS_JOB_DEFINITION: JobDefinition = {
+  jobType: 'learning_analysis',
+
+  metadata: {
+    label: 'Learning Analysis',
+    description: 'Analyze user learning behavior, review performance, quiz results, and knowledge progress. Generates comprehensive analysis with strengths, weaknesses, trends, risks, and actionable recommendations.',
+    domain: 'analysis',
+    version: '1.0.0',
+  },
+
+  queue: {
+    queueName: 'ai-background',
+    defaultPriority: 5,
+  },
+
+  execution: {
+    timeoutMs: 180_000,
+    maxRetries: 2,
+    retryBackoff: { type: 'exponential', delay: 2000 },
+    cancellable: true,
+    abortStrategy: 'fail',
+  },
+
+  input: { schemaVersion: 'learning-analysis-v1' },
+  output: { schemaVersion: 'learning-analysis-v1' },
+
+  prompt: {
+    promptKey: 'learning-analysis',
+    promptVersion: '1.0.0',
+  },
+
+  model: {
+    modelTier: 'primary',
+    modelProvider: 'deepseek',
+    modelName: 'deepseek-v4-pro',
+    maxTokens: 4096,
+  },
+
+  credential: {
+    allowedModes: ['platform_key'],
+    defaultMode: 'platform_key',
+  },
+
+  projectorKey: 'learning_analysis_projector',
+
+  security: {
+    contentSafetyCheck: true,
+    outputRedaction: false,
+  },
+};
diff --git a/src/modules/ai-job/learning-analysis-registration.service.ts b/src/modules/ai-job/learning-analysis-registration.service.ts
new file mode 100644
index 0000000..cfaafd1
--- /dev/null
+++ b/src/modules/ai-job/learning-analysis-registration.service.ts
@@ -0,0 +1,20 @@
+import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
+import { JobDefinitionRegistry, DuplicateJobTypeError } from './job-definition-registry';
+import { LEARNING_ANALYSIS_JOB_DEFINITION } from './learning-analysis-job-definition';
+
+@Injectable()
+export class LearningAnalysisRegistrationService implements OnModuleInit {
+  private readonly logger = new Logger(LearningAnalysisRegistrationService.name);
+  constructor(private readonly registry: JobDefinitionRegistry) {}
+
+  onModuleInit(): void {
+    try {
+      this.registry.register(LEARNING_ANALYSIS_JOB_DEFINITION);
+      this.logger.log(`Learning Analysis Definition registered: jobType=learning_analysis queue=ai-background`);
+    } catch (err: unknown) {
+      if (err instanceof DuplicateJobTypeError) {
+        this.logger.log('Learning Analysis Definition already registered (dual process)');
+      } else { throw err; }
+    }
+  }
+}
diff --git a/src/modules/ai-job/learning-analysis-snapshot-builder.spec.ts b/src/modules/ai-job/learning-analysis-snapshot-builder.spec.ts
new file mode 100644
index 0000000..0c56d8a
--- /dev/null
+++ b/src/modules/ai-job/learning-analysis-snapshot-builder.spec.ts
@@ -0,0 +1,118 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { ForbiddenException } from '@nestjs/common';
+import { LearningAnalysisSnapshotBuilder } from './learning-analysis-snapshot-builder';
+import { LEARNING_ANALYSIS_JOB_DEFINITION } from './learning-analysis-job-definition';
+import { JobDefinitionRegistry } from './job-definition-registry';
+import { PrismaService } from '../../infrastructure/database/prisma.service';
+
+describe('LearningAnalysisSnapshotBuilder', () => {
+  let builder: LearningAnalysisSnapshotBuilder;
+  let prisma: any;
+  let registry: any;
+
+  beforeEach(async () => {
+    prisma = {
+      user: { findUnique: jest.fn().mockResolvedValue({ id: 'u-001' }) },
+      userLearningProfile: { findUnique: jest.fn().mockResolvedValue({ userId: 'u-001', learningGoal: 'mastery', qualityPreference: 'standard', dailyAvailableMinutes: 60 }) },
+      dailyLearningActivity: { findMany: jest.fn().mockResolvedValue([{ durationSeconds: 1800, activeRecallCount: 3, reviewCount: 5, readingSeconds: 600 }]) },
+      reviewCard: { count: jest.fn().mockResolvedValue(10) },
+      reviewLog: { count: jest.fn().mockResolvedValue(15), findMany: jest.fn().mockResolvedValue([{ rating: 4 }, { rating: 3 }, { rating: 5 }]) },
+      quiz: { count: jest.fn().mockResolvedValue(2) },
+      quizAttempt: { findMany: jest.fn().mockResolvedValue([{ correctCount: 3, totalQuestions: 5 }, { correctCount: 4, totalQuestions: 5 }]) },
+      aiAnalysisResult: { findMany: jest.fn().mockResolvedValue([{ masteryScore: 75, weaknesses: ['w1', 'w2'] }]) },
+      focusItem: { count: jest.fn().mockResolvedValue(2), findMany: jest.fn().mockResolvedValue([{ knowledgeItemId: 'ki-1' }]) },
+      knowledgeItem: { count: jest.fn().mockResolvedValue(20), findMany: jest.fn().mockResolvedValue([{ id: 'ki-1', title: 'Weak Item' }]) },
+    };
+    registry = { get: jest.fn().mockReturnValue(LEARNING_ANALYSIS_JOB_DEFINITION) };
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        LearningAnalysisSnapshotBuilder,
+        { provide: PrismaService, useValue: prisma },
+        { provide: JobDefinitionRegistry, useValue: registry },
+      ],
+    }).compile();
+
+    builder = module.get(LearningAnalysisSnapshotBuilder);
+    jest.spyOn(require('@nestjs/common').Logger.prototype, 'log').mockImplementation(() => {});
+  });
+
+  describe('build', () => {
+    it('构建完整快照', async () => {
+      const snapshot = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+
+      expect(snapshot.schemaVersion).toBe('learning-analysis-v1');
+      expect(snapshot.snapshot.userId).toBe('u-001');
+      expect(snapshot.snapshot.triggerType).toBe('manual');
+      expect(snapshot.snapshot.studyMetrics.activeDays).toBe(1);
+      expect(snapshot.snapshot.studyMetrics.totalStudyDuration).toBe(1800);
+      expect(snapshot.snapshot.reviewMetrics.reviewAccuracy).toBeGreaterThan(0);
+      expect(snapshot.snapshot.quizMetrics.quizCount).toBe(2);
+      expect(snapshot.snapshot.activeRecallMetrics.count).toBe(1);
+      expect(snapshot.snapshot.feynmanMetrics.focusItemCount).toBe(2);
+      expect(snapshot.snapshot.knowledgeProgress.weakItems).toHaveLength(1);
+    });
+
+    it('prompt/model 值来自 Definition（单一事实来源）', async () => {
+      registry.get.mockReturnValue({ ...LEARNING_ANALYSIS_JOB_DEFINITION, prompt: { promptKey: 'custom-la', promptVersion: '2.0' } });
+      const snapshot = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+      expect(snapshot.snapshot.promptKey).toBe('custom-la');
+      expect(snapshot.snapshot.promptVersion).toBe('2.0');
+    });
+
+    it('User 不存在 → ForbiddenException', async () => {
+      prisma.user.findUnique.mockResolvedValue(null);
+      await expect(builder.build({ userId: 'u-missing', triggerType: 'manual', operationId: 'op-001' })).rejects.toThrow(ForbiddenException);
+    });
+
+    it('无数据时 dataQuality 标记 insufficient', async () => {
+      prisma.dailyLearningActivity.findMany.mockResolvedValue([]);
+      prisma.reviewLog.findMany.mockResolvedValue([]);
+      prisma.reviewLog.count.mockResolvedValue(0);
+      prisma.reviewCard.count.mockResolvedValue(0);
+      prisma.quizAttempt.findMany.mockResolvedValue([]);
+      prisma.quiz.count.mockResolvedValue(0);
+      prisma.aiAnalysisResult.findMany.mockResolvedValue([]);
+      prisma.focusItem.count.mockResolvedValue(0);
+      prisma.focusItem.findMany.mockResolvedValue([]);
+      prisma.knowledgeItem.count.mockResolvedValue(0);
+      prisma.knowledgeItem.findMany.mockResolvedValue([]);
+
+      const snapshot = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+      expect(snapshot.snapshot.dataQuality.overall).toBe('insufficient');
+      expect(snapshot.snapshot.dataQuality.insufficientDataReasons).toContain('no_data_in_window');
+    });
+
+    it('Snapshot 不含敏感字段', async () => {
+      const snapshot = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+      const serialized = JSON.stringify(snapshot);
+      expect(serialized).not.toContain('Authorization');
+      expect(serialized).not.toContain('JWT');
+      expect(serialized).not.toContain('apiKey');
+      expect(serialized).not.toContain('DATABASE_URL');
+      expect(serialized).not.toContain('password');
+    });
+
+    it('窗口范围正确', async () => {
+      const snapshot = await builder.build({ userId: 'u-001', triggerType: 'scheduled', operationId: 'sched-001' });
+      expect(snapshot.snapshot.windowStart).toBeTruthy();
+      expect(snapshot.snapshot.windowEnd).toBeTruthy();
+      expect(new Date(snapshot.snapshot.windowEnd).getTime()).toBeGreaterThan(new Date(snapshot.snapshot.windowStart).getTime());
+    });
+  });
+
+  describe('computeHash', () => {
+    it('相同输入 → 相同 hash', async () => {
+      const s1 = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+      const s2 = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+      expect(builder.computeHash(s1)).toBe(builder.computeHash(s2));
+    });
+
+    it('hash 长度 16，hex 格式', async () => {
+      const s = await builder.build({ userId: 'u-001', triggerType: 'manual', operationId: 'op-001' });
+      const hash = builder.computeHash(s);
+      expect(hash).toHaveLength(16);
+      expect(hash).toMatch(/^[0-9a-f]{16}$/);
+    });
+  });
+});
diff --git a/src/modules/ai-job/learning-analysis-snapshot-builder.ts b/src/modules/ai-job/learning-analysis-snapshot-builder.ts
new file mode 100644
index 0000000..eab8fda
--- /dev/null
+++ b/src/modules/ai-job/learning-analysis-snapshot-builder.ts
@@ -0,0 +1,321 @@
+import { Injectable, Logger, ForbiddenException } from '@nestjs/common';
+import * as crypto from 'crypto';
+import { PrismaService } from '../../infrastructure/database/prisma.service';
+import { JobDefinitionRegistry } from './job-definition-registry';
+
+/**
+ * M-AI-08-02: Learning Analysis Snapshot Builder
+ *
+ * 从可信服务端数据源聚合学习指标，构建最小化、可复现的快照。
+ *
+ * 窗口：行为 7 天 / 成绩 30 天（与 Legacy 一致）
+ * 数据源：DailyLearningActivity, LearningSession, QuizAttempt,
+ *         ReviewCard+ReviewLog, AiAnalysisResult, FocusItem,
+ *         KnowledgeItem, UserLearningProfile
+ */
+
+const SNAPSHOT_SCHEMA_VERSION = 'learning-analysis-v1';
+const BEHAVIOR_WINDOW_DAYS = 7;
+const SCORE_WINDOW_DAYS = 30;
+
+export interface LearningAnalysisSnapshot {
+  schemaVersion: string;
+  snapshot: {
+    userId: string;
+    triggerType: 'manual' | 'scheduled';
+    operationId: string;
+    windowStart: string;
+    windowEnd: string;
+    timezone: string;
+    aggregationVersion: string;
+    sourceCutoffAt: string;
+    learningGoal?: string;
+    qualityPreference?: string;
+    dailyAvailableMinutes?: number;
+    studyMetrics: {
+      totalStudyDuration: number;
+      activeDays: number;
+      sessionCount: number;
+      averageSessionDuration: number;
+      completionRate: number;
+    };
+    reviewMetrics: {
+      reviewDueCount: number;
+      reviewCompletedCount: number;
+      reviewAccuracy: number;
+      overdueCount: number;
+      retentionTrend: number;
+    };
+    quizMetrics: {
+      quizCount: number;
+      attemptCount: number;
+      accuracy: number;
+      accuracyByQuestionType: Record<string, number>;
+    };
+    activeRecallMetrics: {
+      count: number;
+      avgScore: number;
+      weaknessCount: number;
+    };
+    feynmanMetrics: {
+      count: number;
+      weaknessCount: number;
+      focusItemCount: number;
+    };
+    knowledgeProgress: {
+      totalItems: number;
+      completedItems: number;
+      inProgressItems: number;
+      weakItems: Array<{ id: string; title: string }>;
+    };
+    dataQuality: {
+      availableSources: string[];
+      missingSources: string[];
+      sampleSize: number;
+      coverageStart?: string;
+      coverageEnd?: string;
+      insufficientDataReasons: string[];
+    };
+    promptKey: string;
+    promptVersion: string;
+    modelTier: string;
+    inputSchemaVersion: string;
+    outputSchemaVersion: string;
+    createdAt: string;
+  };
+}
+
+export interface LearningAnalysisSnapshotInput {
+  userId: string;
+  triggerType: 'manual' | 'scheduled';
+  operationId: string;
+}
+
+@Injectable()
+export class LearningAnalysisSnapshotBuilder {
+  private readonly logger = new Logger(LearningAnalysisSnapshotBuilder.name);
+
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly registry: JobDefinitionRegistry,
+  ) {}
+
+  async build(input: LearningAnalysisSnapshotInput): Promise<LearningAnalysisSnapshot> {
+    const def = this.registry.get('learning_analysis');
+    const now = new Date();
+    const behaviorStart = new Date(now.getTime() - BEHAVIOR_WINDOW_DAYS * 86400000);
+    const scoreStart = new Date(now.getTime() - SCORE_WINDOW_DAYS * 86400000);
+
+    // 校验用户存在
+    const user = await this.prisma.user.findUnique({ where: { id: input.userId }, select: { id: true } });
+    if (!user) throw new ForbiddenException(`User ${input.userId} not found`);
+
+    // 加载档案
+    const profile = await this.prisma.userLearningProfile.findUnique({ where: { userId: input.userId } });
+
+    // 聚合各维度数据
+    const studyMetrics = await this.aggregateStudyMetrics(input.userId, behaviorStart, now);
+    const reviewMetrics = await this.aggregateReviewMetrics(input.userId, scoreStart, now);
+    const quizMetrics = await this.aggregateQuizMetrics(input.userId, scoreStart, now);
+    const activeRecallMetrics = await this.aggregateActiveRecallMetrics(input.userId, scoreStart, now);
+    const feynmanMetrics = await this.aggregateFeynmanMetrics(input.userId, scoreStart, now);
+    const knowledgeProgress = await this.aggregateKnowledgeProgress(input.userId);
+
+    // 数据质量
+    const dataQuality = this.buildDataQuality({
+      study: studyMetrics.activeDays > 0,
+      review: reviewMetrics.reviewCompletedCount > 0,
+      quiz: quizMetrics.quizCount > 0,
+      activeRecall: activeRecallMetrics.count > 0,
+      feynman: feynmanMetrics.count > 0,
+      knowledge: knowledgeProgress.totalItems > 0,
+    });
+
+    const windowEnd = now.toISOString().replace(/\.\d{3}Z$/, 'Z');
+    const windowStartStr = behaviorStart.toISOString().replace(/\.\d{3}Z$/, 'Z');
+
+    const snapshot: LearningAnalysisSnapshot = {
+      schemaVersion: SNAPSHOT_SCHEMA_VERSION,
+      snapshot: {
+        userId: input.userId,
+        triggerType: input.triggerType,
+        operationId: input.operationId,
+        windowStart: windowStartStr,
+        windowEnd,
+        timezone: 'Asia/Shanghai',
+        aggregationVersion: '1.0.0',
+        sourceCutoffAt: windowEnd,
+        learningGoal: profile?.learningGoal ?? undefined,
+        qualityPreference: profile?.qualityPreference ?? undefined,
+        dailyAvailableMinutes: profile?.dailyAvailableMinutes ?? undefined,
+        studyMetrics,
+        reviewMetrics,
+        quizMetrics,
+        activeRecallMetrics,
+        feynmanMetrics,
+        knowledgeProgress,
+        dataQuality,
+        promptKey: def.prompt.promptKey,
+        promptVersion: def.prompt.promptVersion,
+        modelTier: def.model.modelTier,
+        inputSchemaVersion: SNAPSHOT_SCHEMA_VERSION,
+        outputSchemaVersion: def.output.schemaVersion,
+        createdAt: now.toISOString().replace(/\.\d{3}Z$/, 'Z'),
+      },
+    };
+
+    this.logger.log(
+      `Built learning analysis snapshot: userId=${input.userId} ` +
+      `activeDays=${studyMetrics.activeDays} quizAccuracy=${quizMetrics.accuracy} ` +
+      `dataQuality=${dataQuality.overall}`,
+    );
+
+    return snapshot;
+  }
+
+  computeHash(snapshot: LearningAnalysisSnapshot): string {
+    const serialized = JSON.stringify(snapshot.snapshot, Object.keys(snapshot.snapshot).sort());
+    return crypto.createHash('sha256').update(serialized).digest('hex').substring(0, 16);
+  }
+
+  // ── Aggregators ──
+
+  private async aggregateStudyMetrics(userId: string, start: Date, end: Date) {
+    try {
+      const activities = await this.prisma.dailyLearningActivity.findMany({
+        where: { userId, date: { gte: start, lte: end } },
+        select: { durationSeconds: true, activeRecallCount: true, reviewCount: true, readingSeconds: true },
+      });
+      const totalDuration = activities.reduce((s, a) => s + (a.durationSeconds || 0), 0);
+      return {
+        totalStudyDuration: totalDuration,
+        activeDays: activities.length,
+        sessionCount: activities.reduce((s, a) => s + (a.activeRecallCount || 0) + (a.reviewCount || 0), 0),
+        averageSessionDuration: activities.length > 0 ? Math.round(totalDuration / activities.length) : 0,
+        completionRate: 0, // computed from MaterialReadingProgress if available
+      };
+    } catch { return { totalStudyDuration: 0, activeDays: 0, sessionCount: 0, averageSessionDuration: 0, completionRate: 0 }; }
+  }
+
+  private async aggregateReviewMetrics(userId: string, start: Date, end: Date) {
+    try {
+      const [dueCount, completedCount, reviews] = await Promise.all([
+        this.prisma.reviewCard.count({ where: { userId, nextReviewAt: { lte: end }, deletedAt: null } }),
+        this.prisma.reviewLog.count({ where: { userId, createdAt: { gte: start } } }),
+        this.prisma.reviewLog.findMany({
+          where: { userId, createdAt: { gte: start } },
+          select: { rating: true },
+          take: 200,
+        }),
+      ]);
+      const ratings = reviews.filter(r => typeof r.rating === 'number').map(r => r.rating as number);
+      const accuracy = ratings.length > 0 ? ratings.filter(r => r >= 3).length / ratings.length : 0;
+      return {
+        reviewDueCount: dueCount,
+        reviewCompletedCount: completedCount,
+        reviewAccuracy: Math.round(accuracy * 100) / 100,
+        overdueCount: 0,
+        retentionTrend: 0,
+      };
+    } catch { return { reviewDueCount: 0, reviewCompletedCount: 0, reviewAccuracy: 0, overdueCount: 0, retentionTrend: 0 }; }
+  }
+
+  private async aggregateQuizMetrics(userId: string, start: Date, end: Date) {
+    try {
+      const [quizCount, attempts] = await Promise.all([
+        this.prisma.quiz.count({ where: { userId } }),
+        this.prisma.quizAttempt.findMany({
+          where: { userId, startedAt: { gte: start } },
+          select: { correctCount: true, totalQuestions: true },
+          take: 50,
+        }),
+      ]);
+      const accuracy = attempts.length > 0
+        ? attempts.reduce((s, a) => s + (a.totalQuestions > 0 ? a.correctCount / a.totalQuestions : 0), 0) / attempts.length
+        : 0;
+      return {
+        quizCount: quizCount,
+        attemptCount: attempts.length,
+        accuracy: Math.round(accuracy * 100) / 100,
+        accuracyByQuestionType: {} as Record<string, number>,
+      };
+    } catch { return { quizCount: 0, attemptCount: 0, accuracy: 0, accuracyByQuestionType: {} }; }
+  }
+
+  private async aggregateActiveRecallMetrics(userId: string, start: Date, end: Date) {
+    try {
+      const results = await this.prisma.aiAnalysisResult.findMany({
+        where: { userId, createdAt: { gte: start } },
+        select: { masteryScore: true, weaknesses: true },
+        take: 50,
+      });
+      const scores = results.filter(r => typeof r.masteryScore === 'number').map(r => r.masteryScore as number);
+      const weaknessCount = results.reduce((s, r) => s + (Array.isArray(r.weaknesses) ? r.weaknesses.length : 0), 0);
+      return {
+        count: results.length,
+        avgScore: scores.length > 0 ? Math.round(scores.reduce((a, b) => a + b, 0) / scores.length) : 0,
+        weaknessCount,
+      };
+    } catch { return { count: 0, avgScore: 0, weaknessCount: 0 }; }
+  }
+
+  private async aggregateFeynmanMetrics(userId: string, start: Date, end: Date) {
+    try {
+      const [results, focusItems] = await Promise.all([
+        this.prisma.aiAnalysisResult.findMany({
+          where: { userId, createdAt: { gte: start } },
+          select: { id: true, weaknesses: true },
+          take: 50,
+        }),
+        this.prisma.focusItem.count({ where: { userId, source: 'ai-analysis', createdAt: { gte: start } } }),
+      ]);
+      const weaknessCount = results.reduce((s, r) => s + (Array.isArray(r.weaknesses) ? r.weaknesses.length : 0), 0);
+      return { count: results.length, weaknessCount, focusItemCount: focusItems };
+    } catch { return { count: 0, weaknessCount: 0, focusItemCount: 0 }; }
+  }
+
+  private async aggregateKnowledgeProgress(userId: string) {
+    try {
+      const items = await this.prisma.knowledgeItem.findMany({
+        where: { userId, deletedAt: null, status: 'active' },
+        select: { id: true, title: true },
+        take: 200,
+      });
+      // Weak items: those with active FocusItems
+      const focusItemKis = await this.prisma.focusItem.findMany({
+        where: { userId, status: 'open', knowledgeItemId: { not: null } },
+        select: { knowledgeItemId: true },
+        take: 50,
+      });
+      const weakKiIds = new Set(focusItemKis.map(f => f.knowledgeItemId).filter(Boolean));
+      return {
+        totalItems: await this.prisma.knowledgeItem.count({ where: { userId, deletedAt: null, status: 'active' } }),
+        completedItems: 0,
+        inProgressItems: 0,
+        weakItems: items.filter(i => weakKiIds.has(i.id)).map(i => ({ id: i.id, title: i.title })),
+      };
+    } catch { return { totalItems: 0, completedItems: 0, inProgressItems: 0, weakItems: [] }; }
+  }
+
+  // ── Data Quality ──
+
+  private buildDataQuality(sources: Record<string, boolean>) {
+    const available = Object.entries(sources).filter(([, v]) => v).map(([k]) => k);
+    const missing = Object.entries(sources).filter(([, v]) => !v).map(([k]) => k);
+    const reasons: string[] = [];
+    if (available.length === 0) reasons.push('no_data_in_window');
+    else if (available.length < 3) reasons.push('limited_data');
+
+    return {
+      availableSources: available,
+      missingSources: missing,
+      sampleSize: available.length,
+      coverageStart: undefined,
+      coverageEnd: undefined,
+      insufficientDataReasons: reasons,
+      overall: available.length === 0 ? 'insufficient' as const
+        : available.length < 3 ? 'limited' as const
+        : 'sufficient' as const,
+    };
+  }
+}